public static void SetToggleArrowPlacement(TreeView treeView, ToggleArrowPlacement value)
 {
     treeView.SetValue(ToggleArrowPlacementProperty, value);
 }
 public static void SetToggleArrowPlacement(Expander expander, ToggleArrowPlacement value)
 {
     expander.SetValue(ToggleArrowPlacementProperty, value);
 }